| java.lang.Object
 org.apache.commons.collections.map.CompositeMap
| CompositeMap | | public class CompositeMap implements Map(Code) | | Decorates a map of other maps to provide a single unified view.
Changes made to this map will actually be made on the decorated map.
Add and remove operations require the use of a pluggable strategy. If no
strategy is provided then add and remove are unsupported.
Note that CompositeMap is not synchronized and is not thread-safe.
If you wish to use this map from multiple threads concurrently, you must use
appropriate synchronization. The simplest approach is to wrap this map
using
java.util.Collections.synchronizedMap(Map) . This class may throw
exceptions when accessed by concurrent threads without synchronization.
since:
Commons Collections 3.0
version:
$Revision: 348007 $ $Date: 2005-11-21 22:52:57 +0000 (Mon, 21 Nov 2005) $
author:
Brian McCallister |
| Inner Class :public static interface MapMutator | |
| Constructor Summary | |
| public | CompositeMap()
Create a new, empty, CompositeMap. | | public | CompositeMap(Map one, Map two)
Create a new CompositeMap with two composited Map instances. | | public | CompositeMap(Map one, Map two, MapMutator mutator)
Create a new CompositeMap with two composited Map instances. | | public | CompositeMap(Map[] composite)
Create a new CompositeMap which composites all of the Map instances in the
argument. | | public | CompositeMap(Map[] composite, MapMutator mutator)
Create a new CompositeMap which composites all of the Map instances in the
argument. |
| Method Summary | |
| public synchronized void | addComposited(Map map)
Add an additional Map to the composite. | | public void | clear()
Calls clear() on all composited Maps. | | public boolean | containsKey(Object key)
Returns true if this map contains a mapping for the specified
key. | | public boolean | containsValue(Object value)
Returns true if this map maps one or more keys to the
specified value. | | public Set | entrySet()
Returns a set view of the mappings contained in this map. | | public boolean | equals(Object obj)
Checks if this Map equals another as per the Map specification. | | public Object | get(Object key)
Returns the value to which this map maps the specified key. | | public int | hashCode()
Gets a hash code for the Map as per the Map specification. | | public boolean | isEmpty()
Returns true if this map contains no key-value mappings. | | public Set | keySet()
Returns a set view of the keys contained in this map. | | public Object | put(Object key, Object value)
Associates the specified value with the specified key in this map
(optional operation). | | public void | putAll(Map map)
Copies all of the mappings from the specified map to this map
(optional operation). | | public Object | remove(Object key)
Removes the mapping for this key from this map if it is present
(optional operation). | | public synchronized Map | removeComposited(Map map)
Remove a Map from the composite. | | public void | setMutator(MapMutator mutator)
Specify the MapMutator to be used by mutation operations. | | public int | size()
Returns the number of key-value mappings in this map. | | public Collection | values()
Returns a collection view of the values contained in this map. |
| CompositeMap | | public CompositeMap()(Code) | | Create a new, empty, CompositeMap.
|
| CompositeMap | | public CompositeMap(Map one, Map two)(Code) | | Create a new CompositeMap with two composited Map instances.
Parameters:
one - the first Map to be composited
Parameters:
two - the second Map to be composited
throws:
IllegalArgumentException - if there is a key collision |
| CompositeMap | | public CompositeMap(Map one, Map two, MapMutator mutator)(Code) | | Create a new CompositeMap with two composited Map instances.
Parameters:
one - the first Map to be composited
Parameters:
two - the second Map to be composited
Parameters:
mutator - MapMutator to be used for mutation operations |
| CompositeMap | | public CompositeMap(Map[] composite)(Code) | | Create a new CompositeMap which composites all of the Map instances in the
argument. It copies the argument array, it does not use it directly.
Parameters:
composite - the Maps to be composited
throws:
IllegalArgumentException - if there is a key collision |
| CompositeMap | | public CompositeMap(Map[] composite, MapMutator mutator)(Code) | | Create a new CompositeMap which composites all of the Map instances in the
argument. It copies the argument array, it does not use it directly.
Parameters:
composite - Maps to be composited
Parameters:
mutator - MapMutator to be used for mutation operations |
| addComposited | | public synchronized void addComposited(Map map) throws IllegalArgumentException(Code) | | Add an additional Map to the composite.
Parameters:
map - the Map to be added to the composite
throws:
IllegalArgumentException - if there is a key collision and there is noMapMutator set to handle it. |
| containsKey | | public boolean containsKey(Object key)(Code) | | Returns true if this map contains a mapping for the specified
key. More formally, returns true if and only if
this map contains at a mapping for a key k such that
(key==null ? k==null : key.equals(k)). (There can be
at most one such mapping.)
Parameters:
key - key whose presence in this map is to be tested. true if this map contains a mapping for the specifiedkey.
throws:
ClassCastException - if the key is of an inappropriate type forthis map (optional).
throws:
NullPointerException - if the key is null and this mapdoes not not permit null keys (optional). |
| containsValue | | public boolean containsValue(Object value)(Code) | | Returns true if this map maps one or more keys to the
specified value. More formally, returns true if and only if
this map contains at least one mapping to a value v such that
(value==null ? v==null : value.equals(v)). This operation
will probably require time linear in the map size for most
implementations of the Map interface.
Parameters:
value - value whose presence in this map is to be tested. true if this map maps one or more keys to thespecified value.
throws:
ClassCastException - if the value is of an inappropriate type forthis map (optional).
throws:
NullPointerException - if the value is null and this mapdoes not not permit null values (optional). |
| entrySet | | public Set entrySet()(Code) | | Returns a set view of the mappings contained in this map. Each element
in the returned set is a Map.Entry. The set is backed by the
map, so changes to the map are reflected in the set, and vice-versa.
If the map is modified while an iteration over the set is in progress,
the results of the iteration are undefined. The set supports element
removal, which removes the corresponding mapping from the map, via the
Iterator.remove, Set.remove, removeAll,
retainAll and clear operations. It does not support
the add or addAll operations.
This implementation returns a CompositeSet which
composites the entry sets from all of the composited maps.
See Also: CompositeSet a set view of the mappings contained in this map. |
| equals | | public boolean equals(Object obj)(Code) | | Checks if this Map equals another as per the Map specification.
Parameters:
obj - the object to compare to true if the maps are equal |
| get | | public Object get(Object key)(Code) | | Returns the value to which this map maps the specified key. Returns
null if the map contains no mapping for this key. A return
value of null does not necessarily indicate that the
map contains no mapping for the key; it's also possible that the map
explicitly maps the key to null. The containsKey
operation may be used to distinguish these two cases.
More formally, if this map contains a mapping from a key
k to a value v such that (key==null ? k==null :
key.equals(k)), then this method returns v; otherwise
it returns null. (There can be at most one such mapping.)
Parameters:
key - key whose associated value is to be returned. the value to which this map maps the specified key, ornull if the map contains no mapping for this key.
throws:
ClassCastException - if the key is of an inappropriate type forthis map (optional).
throws:
NullPointerException - key is null and this map does notnot permit null keys (optional).
See Also: CompositeMap.containsKey(Object) |
| hashCode | | public int hashCode()(Code) | | Gets a hash code for the Map as per the Map specification.
|
| isEmpty | | public boolean isEmpty()(Code) | | Returns true if this map contains no key-value mappings.
true if this map contains no key-value mappings. |
| keySet | | public Set keySet()(Code) | | Returns a set view of the keys contained in this map. The set is
backed by the map, so changes to the map are reflected in the set, and
vice-versa. If the map is modified while an iteration over the set is
in progress, the results of the iteration are undefined. The set
supports element removal, which removes the corresponding mapping from
the map, via the Iterator.remove, Set.remove,
removeAll retainAll, and clear operations.
It does not support the add or addAll operations.
This implementation returns a CompositeSet which
composites the key sets from all of the composited maps.
a set view of the keys contained in this map. |
| put | | public Object put(Object key, Object value)(Code) | | Associates the specified value with the specified key in this map
(optional operation). If the map previously contained a mapping for
this key, the old value is replaced by the specified value. (A map
m is said to contain a mapping for a key k if and only
if
CompositeMap.containsKey(Object) m.containsKey(k) would return
true.))
Parameters:
key - key with which the specified value is to be associated.
Parameters:
value - value to be associated with the specified key. previous value associated with specified key, or nullif there was no mapping for key. A null return canalso indicate that the map previously associated nullwith the specified key, if the implementation supportsnull values.
throws:
UnsupportedOperationException - if no MapMutator has been specified
throws:
ClassCastException - if the class of the specified key or valueprevents it from being stored in this map.
throws:
IllegalArgumentException - if some aspect of this key or valueprevents it from being stored in this map.
throws:
NullPointerException - this map does not permit nullkeys or values, and the specified key or value isnull. |
| putAll | | public void putAll(Map map)(Code) | | Copies all of the mappings from the specified map to this map
(optional operation). The effect of this call is equivalent to that
of calling
CompositeMap.put(Object,Object) put(k, v) on this map once
for each mapping from key k to value v in the
specified map. The behavior of this operation is unspecified if the
specified map is modified while the operation is in progress.
Parameters:
map - Mappings to be stored in this map.
throws:
UnsupportedOperationException - if the putAll method isnot supported by this map.
throws:
ClassCastException - if the class of a key or value in thespecified map prevents it from being stored in this map.
throws:
IllegalArgumentException - some aspect of a key or value in thespecified map prevents it from being stored in this map.
throws:
NullPointerException - the specified map is null, or ifthis map does not permit null keys or values, and thespecified map contains null keys or values. |
| remove | | public Object remove(Object key)(Code) | | Removes the mapping for this key from this map if it is present
(optional operation). More formally, if this map contains a mapping
from key k to value v such that
(key==null ? k==null : key.equals(k)), that mapping
is removed. (The map can contain at most one such mapping.)
Returns the value to which the map previously associated the key, or
null if the map contained no mapping for this key. (A
null return can also indicate that the map previously
associated null with the specified key if the implementation
supports null values.) The map will not contain a mapping for
the specified key once the call returns.
Parameters:
key - key whose mapping is to be removed from the map. previous value associated with specified key, or nullif there was no mapping for key.
throws:
ClassCastException - if the key is of an inappropriate type forthe composited map (optional).
throws:
NullPointerException - if the key is null and the composited mapdoes not not permit null keys (optional).
throws:
UnsupportedOperationException - if the remove method isnot supported by the composited map containing the key |
| removeComposited | | public synchronized Map removeComposited(Map map)(Code) | | Remove a Map from the composite.
Parameters:
map - the Map to be removed from the composite The removed Map or null if map is not in the composite |
| setMutator | | public void setMutator(MapMutator mutator)(Code) | | Specify the MapMutator to be used by mutation operations.
Parameters:
mutator - the MapMutator to be used for mutation delegation |
| size | | public int size()(Code) | | Returns the number of key-value mappings in this map. If the
map contains more than Integer.MAX_VALUE elements, returns
Integer.MAX_VALUE.
the number of key-value mappings in this map. |
| values | | public Collection values()(Code) | | Returns a collection view of the values contained in this map. The
collection is backed by the map, so changes to the map are reflected in
the collection, and vice-versa. If the map is modified while an
iteration over the collection is in progress, the results of the
iteration are undefined. The collection supports element removal,
which removes the corresponding mapping from the map, via the
Iterator.remove, Collection.remove,
removeAll, retainAll and clear operations.
It does not support the add or addAll operations.
a collection view of the values contained in this map. |
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